It can take a bit of playing around with plate coil turns, and link turns, to get the best power output and efficiency.
I see the BC610 DOES do triode link coupled output...bet it's a bit tricky to neutralize, then you would have to set up each band coil? I never had a BC610, was it a pain to neutralize on each band? Brett -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Donald Chester Sent: Thursday, September 22, 2005 10:34 PM To: amradio@mailman.qth.net Subject: Re: [AMRadio] Pi-Net vs Link Couple >I wonder though Don, while I've got your .. uhm 'ear' (eyes?) The link >could use a little tuning to take a bit more load in the final. I've >modified one of my 80m B&W HDVL plug-in coils and removed two turns on >each side (4 turns, total), to raise the plate current a bit, because the Q >is a bit sharp in that circuit. A breif excursion off-resonance, w/1.5kWDC >on the plates, draws around 550mA. At Resonance (with 125mA of grid drive) >the thing dips to around 200mA. That said, what value of series >capacitance would you suggest/recommend to tune the link? In mine, I use a 4-turn link. On 80m I have about a 1000 pf air variable directly in series with the link, and I think about 300 pf is actually meshed in for resonance. On 160 I use a capacitive voltage divider formed by two fixed micas in series (about .002 each) with the 1000 pf variable bridged across one of them for fine tuning. The load is placed across one of the caps. I can get good coupling that way. When I tried a simple series cap on 160, I could hit resonance, but could only get about 10% coupling. On 40 I use the series cap, but it is almost completely unmeshed to hit resonance. I duplicated the setup for my other homebrew rig, and it works identically. 73, Don ______________________________________________________________ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami
